This invention relates to a fuel cell system and more particularly to an improved arrangement for operating a fuel cell to insure that it is brought to its operating temperature as rapidly as possible and to insure that the fuel cell does not become overheated.
It is well known that electrical energy can be supplied from a fuel cell that reacts an enriched or reformed fuel with air to produce electrical energy. Such systems include a cell that has fuel and air poles with an electrolyte matrix impregnated with an electrolyte such as phosphoric acid interposed therebetween. The devices operate with a hydrogen rich reformed gaseous fuel that produces electrical power and water through an electrical chemical reaction which is exothermic in nature. Because of the exothermic nature of the reaction, the fuel cell is generally operated at a temperature in the range of 200.degree. C. and has its temperature maintained by means of a cooling jacket. However, when starting up the fuel cell, it is important to insure that the operating temperature is reached as soon as possible so as to permit full power utilization and insure against the loss of energy.
Devices have been proposed for insuring more rapid start up through the use of heaters for the air supply system that supplies the air to the air pole of the fuel cell. However, such devices complicate the system and also require electrical energy for their operation, thus somewhat defeating their purpose. It has also been proposed to raise the fuel cell system temperature by temporarily supplying heated gas exhaust from the reformer to the cooling jacket. However, the circulation of the heated exhaust air from the reformer to the cooling jacket considerably complicates the piping and plumbing system and also can give rise to the possibility of overheating.
It is, therefore, a principal object of this invention to provide an improved, simplified and highly effective fuel cell.
It is a further object of this invention to provide a fuel cell arrangement wherein the fuel cell can be brought up to its operating temperature as soon as possible without the use of extraneous heating devices.
It is a further object of this invention to provide an improved system for heating a fuel cell to its operating temperature through-the use of the exhaust gases from the reformer as a heating device for this cell without necessitating a separate heating jacket or the use of these gases in the cooling jacket of the cell.